Synthesis of 4-Triazolylamino- and 4-Benzothiazolylamino-3-nitro-2H-[1]-Benzopyran-2-ones and their Antimicrobial Activity

• Main Authors: Ramiz Hoti, Aferdita Nura-Lama, Gjyle Mulliqi-Osmani, Naser Troni, Fatbardh Gashi, Hamit Ismaili, Veprim Thaci
• Format: Article
• Language: English
• Published: Universidade Federal de Mato Grosso do Sul 2014-10-01
• Series: Orbital: The Electronic Journal of Chemistry
• Subjects: benzopyran-2-one; triazolylamine; benzothiazolylamine; antibacterial activity
• Online Access: http://orbital.ufms.br/index.php/Chemistry/article/view/564

Novel substituted benzopyran-2-one derivatives were synthesized by catalytic condensation reactions under reflux conditions. 4-(1,2,4-Triazolyl-3-amino)-3-nitro-2H-[1]-benzopyran-2-ones <strong>4(a-b)</strong> were synthesized by condensation of 4-chloro-3-nitro-2H-[1]-benzopyran-2-one (<strong>2</strong>) and corresponding 3-aminotriazoles <strong>3(a-b)</strong>. 4-(4’-methoxy-2-benzothiazolylamino)-3-nitro-2H-[1]-benzopyran-2-one (<strong>4c</strong>), 4-(6’-nitro-2-benzothiazolylamino)-3-nitro-2H-[1]-benzopyiran-2-one (<strong>4d</strong>) and 4-(6’-fluoro-2-benzothiazolylamino)-3-nitro-2H-[1]-benzopyran-2-one (<strong>4e</strong>) were synthesized by condensation of 4-chloro-3-nitro-2H-[1]-benzopyran-2-one (<strong>2</strong>) and corresponding 2-aminobenzothiazole <strong>3(c-e)</strong> under reflux reaction conditions. Further, alkali hydrolysis of <strong>4(a-e)</strong> afforded the 2-hydroxy-ω-nitroacetophenone (<strong>5</strong>). Antimicrobial activity of products <strong>4(a-e)</strong> against <em>S. aurous</em>, <em>E. coli</em> and <em>Klebsiella</em> were investigated measuring of inhibition zones around the discs which are marked with DMF, concentration 2 mg/mL, 4 mg/mL and 6 mg/mL solutions. Compounds <strong>4c</strong>, <strong>4e</strong> and <strong>4d </strong>were more active against <em>S. aureus.</em> Emphatic activity against <em>E. coli</em> exhibited compounds <strong>4b</strong> and <strong>4e</strong>, whereas <strong>4c</strong> and <strong>4d</strong> were more active against <em>Klebsiella</em>.<br />